JoXSZ: Joint X-SZ fitting code for galaxy clusters
Journal
Date Issued
2020
Author(s)
Abstract
The thermal Sunyaev-Zeldovich (SZ) effect and the X-ray emission offer
separate and highly complementary probes of the thermodynamics of the
intracluster medium. We present JoXSZ, the first publicly available code
designed to jointly fit SZ and X-ray data coming from various instruments to
derive the thermodynamic profiles of galaxy clusters. JoXSZ follows a fully
Bayesian forward-modelling approach, accounts for the SZ calibration
uncertainty and X-ray background level systematic. It improves upon most
state-of-the-art, and not publicly available, analyses because it adopts the
correct Poisson-Gauss expression for the joint likelihood, makes full use of
the information contained in the observations, even in the case of missing
values within the datasets, has a more inclusive error budget, and adopts a
consistent temperature across the various parts of the code, allowing for
differences between X-ray and SZ gas mass weighted temperatures when required
by the user. JoXSZ accounts for beam smearing and data analysis transfer
function, accounts for the temperature and metallicity dependencies of the SZ
and X-ray conversion factors, adopts flexible parametrization for the
thermodynamic profiles, and on user request allows either adopting or relaxing
the assumption of hydrostatic equilibrium (HE). When HE holds, JoXSZ uses a
physical (positive) prior on the radial derivative of the enclosed mass and
derives the mass profile and overdensity radii $r_\Delta$. For these reasons,
JoXSZ goes beyond simple SZ and electron density fits. We illustrate the use of
JoXSZ by combining Chandra and NIKA data on the high-redshift cluster CL
J1226.9+3332. The code is written in Python, it is fully documented and the
users are free to customize their analysis in accordance with their needs and
requirements. JoXSZ is publicly available on GitHub.
Volume
639
Start page
A73
Issn Identifier
0004-6361
Ads BibCode
2020A&A...639A..73C
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
2020_JoXSZ.pdf
Description
Pdf editoriale
Size
4.72 MB
Format
Adobe PDF
Checksum (MD5)
bf2489490a375560f576d2c252b2a5ce